Y-branch pipe i.e. Y-pipe, for exhaust gas system of e.g. diesel engine of motor vehicles, has pipe section, where preceding bending treatment is drawn up on pipe section that is not permanently bent by intended operation of engine

摘要

The pipe (1) has an inner pipe section (2) surrounded by a high temperature-resistant insulation (3). A protective sheathing (4) is formed as a curved arcuate metallic protective sheathing e.g. flexible metallic duct element such as flexible metallic pipe, metal bellows or metal compensator. The sheathing is dimensioned such that the sheathing is more bendable and longitudinally wound up by performing a bending treatment on the pipe section. Preceding bending treatment is drawn up on the pipe section that is not permanently bent by intended operation of an internal combustion engine. The insulation is selected from a group consisting of a fiber product e.g. glass fiber product, artificial mineral fiber product or fiber mixtures such as polymeric fibers, natural fibers or artificial mineral fibers, a thread, a fabric, a knitted fabric, a round knitted fabric, a flat knitting fabric, core, parallel mesh, cotton, non-woven fabric, wool or fiber molding. An independent claim is also included for a method for manufacturing a Y-branch pipe for an exhaust gas system of an internal combustion engine.